Since you don’t need a specialized rack, you should probably consider shops and magazines that emphasize home decor. Ikea or wayfair, also houzz - on-line should give you plenty of ideas. good luck and keep enjoying the music.
Is there a reason for wanting them separate ?? OK I understand if the router is already separated by location, but if its because you think it has SQ gains, I’m not sure that is worth pursuing.
I experimented a few years back router-NAS-streamer & found no audible difference either way. Because the incoming phone line was a job & a half to wire to a LAN switch & to the streamer, I bit the bullet & had BT move the phone entry to be close to my prefered location for phone & broadband hub. I now have it all located close together.
Re rack - I share your frustration, I made my own - 3 classic sized boxes visible & 2 cuddly toy boxes hidden behind the cabinet door.
Another shout for the BESTA. I house my RP8, NAT01, Aria, TTPS, Cisco switch and Unitiserve along with some LPs in one.
I have Naim cups and balls with glass for isolation on the top (for the RP8 and NAT01). This is in combination with the Fraim for the amps, PS and NDS but it is good value, looks fine and is really adaptable with doors, internal glass shelving and removable back panels all available depending on individual requirements.
For me it has the added advantage of keeping the Unitiserve’s hard drive behind a glass door and therefore quiet as it is quite noisy when left out in the open.